Rollback protection system and method

ABSTRACT

A method for preventing rollback of a rail vehicle from a stopped condition, includes receiving a first signal indicative of the rail vehicle&#39;s location, and, in response to the first signal, selecting from a lookup table one of a first plurality of pre-determined values of a braking parameter and selecting from the lookup table one of a second plurality of pre-determined values of a tractive effort parameter. In response to an order for movement, the method includes applying brakes of the rail vehicle, according to the selected value of the braking parameter; establishing tractive effort of the rail vehicle, according to the selected value of the tractive effort parameter; and, then, releasing the brakes of the rail vehicle to establish motion of the rail vehicle from the stopped condition.

BACKGROUND

1. Technical Field

Embodiments of the invention relate generally to control systems for rail vehicles.

2. Discussion of Art

Rail car switching, shunting, and classification are integral aspects of rail freight operations. These procedures are performed in switching yards or classification yards, which include multiple rail tracks branching from one or more lead tracks and joining together at one or more exits. To maximize operational efficiency, several cars or trains of cars are typically moving simultaneously along different branches within a yard. Due to the presence of multiple stationary rail cars or stub trains on intervening tracks, an operator in a locomotive moving on a first track may not be able to see moving cars on a track branching from the first track. Accordingly, locomotive operators may coordinate their actions via a yardmaster stationed in a control tower overlooking the yard.

Three-way communication between operators and a yardmaster can potentially introduce lag time and error, which are undesirable while moving multiple pieces of heavy rail equipment. As such, some yards include systems by which a yardmaster may remotely control and coordinate movement of multiple stub trains (“tower control systems”).

In situations where the train may be on a grade (as may be found in connection with mining operations), there is a known tendency for “rollback” where the train moves opposite the applied tractive power. While rollback can often be quickly detected and corrected by an onboard operator, the phenomenon is more difficult to detect and slower to correct from a remote location such as would be occupied by a tower control system operator. Yet as discussed above, rail yard operations, generally, can be accomplished more efficiently by a tower control system operator than by an onboard crew. As will be appreciated, it is inefficient and undesirable to continuously crew a train in a rail yard, solely for the purpose of preventing rollback, particularly where the onboard crew might otherwise interfere with tower control system operation. As such, it is desirable to provide a tower control system that includes a specific and automated method to prevent rollback.

BRIEF DESCRIPTION

In embodiments, a system for controlling a rail vehicle includes an off-board control unit that is configured for communication with an on-board transceiver, which is mounted in the rail vehicle. The off-board control unit is further configured to receive a first signal indicative of a location of the rail vehicle and to, in response to the indicated location of the rail vehicle matching a pre-defined list of rollback locations, send to the on-board transceiver a second signal indicative of a tractive effort parameter corresponding to at least the indicated location of the rail vehicle.

In aspects, a method, e.g., a method for preventing rollback of a rail vehicle from a stopped condition, includes receiving a first signal indicative of the rail vehicle's location and, in response to the first signal, selecting from a lookup table one of a first plurality of pre-determined values of a braking parameter and selecting from the lookup table one of a second plurality of pre-determined values of a tractive effort parameter. The method then includes transmitting to the rail vehicle a second signal ordering movement of the rail vehicle from the stopped condition. The second signal includes the selected value of the braking parameter for controlling application of brakes of the rail vehicle and the selected value of the tractive effort parameter for establishing tractive effort of the rail vehicle.

In embodiments, a system for controlling a rail vehicle includes an on-board transceiver mounted in the rail vehicle and operatively connected with at least one traction motor and at least one brake of the rail vehicle. The on-board transceiver is configured to receive from an off-board control unit a first signal for establishing a rollback prevention mode. In its rollback prevention mode, the on-board transceiver is configured to receive from the off-board control unit a second signal indicative of a required tractive effort and a third signal indicative of a required braking force, and to control maintaining the required braking force until attaining the required tractive effort.

In embodiments, a system for controlling a rail vehicle includes an off-board control unit that is not mounted in the rail vehicle and an on-board transceiver that is mounted in the rail vehicle. The off-board control unit is configured to receive a first signal indicative of a location of the rail vehicle and to send, in response to the first signal, a second signal indicative of a minimum tractive effort parameter and a third signal indicative of a braking parameter. The on-board transceiver is operatively connected with at least one traction motor and at least one brake of the rail vehicle, and is configured to receive the second and third signals from the off-board control unit. The on-board transceiver is further configured to control maintaining the brake output at or above a level of the braking parameter until the traction motor output at least matches a level of the minimum tractive effort parameter.

DRAWINGS

The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:

FIG. 1 shows in schematic view a bulk cargo loading/unloading operation including a tower control system according to one aspect of the present invention.

FIG. 2 shows in schematic view a rollback phenomenon.

FIG. 3 shows in schematic view a tower control system according to an embodiment of the present invention.

FIG. 4 shows in schematic view details of the tower control system shown in FIG. 3.

FIG. 5 shows in schematic view operation of the tower control system shown in FIGS. 3 and 4.

FIGS. 6A-6C show in schematic view a rollback prevention mode of the tower control system, according to aspects of the present invention.

FIG. 7 shows in schematic view a rollback prevention mode of the tower control system, according to other aspects of the present invention.

FIGS. 8A-8B show in schematic view another rollback prevention mode of the tower control system, according to other aspects of the present invention.

DETAILED DESCRIPTION

Reference will be made below in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference characters used throughout the drawings refer to the same or like parts. Although exemplary embodiments of the present invention are described with respect to rail vehicles within a rail yard, embodiments of the invention are also applicable for use with rail vehicles, generally.

FIG. 1 shows in schematic view a bulk cargo loading/unloading operation 10 that includes a loop (or other section) of track 12 connected from a main rail line 14 through loading/unloading equipment 16. In the loading/unloading equipment 16, coal/iron ore/other bulk products are dumped into or out of cars or wagons 18 of a train or other rail vehicle consist 20 that is located at a location on the loop of track 12. (A rail vehicle consist is a group of rail vehicles that are mechanically linked to travel together along a track.) For example, the loading/unloading equipment 16 may include a dumper chute (which directs a continuous flow of bulk material into a wagon positioned below the chute) or a rotary dumper cage (which inverts a wagon positioned in the dumper cage).

When the rail vehicle consist 20 approaches the unloading equipment 16, each wagon 18 is in turn moved into position by indexing equipment 22. Once a wagon 18 is positioned, independent and/or automatic brakes are set to hold the rail vehicle consist 20 at a fixed location. (“Independent brakes” means the brakes of each locomotive or other powered rail vehicle 24 (rail vehicle capable of self propulsion) within the rail vehicle consist 20, which can be controlled independently of the “automatic brakes” that are installed on each wagon 18. The automatic brakes installed on the wagons 18 are operable all together and are also referred to as “train brakes.” Together, the independent and automatic brakes compose a “braking system,” which may be operated all together or piece by piece.)

In order to move the whole rail vehicle consist 20 forward, so as to bring a next wagon 18 into position, the brakes must be released while tractive power is applied when all or part of the rail vehicle consist 20 is located on a grade or incline, then rollback (as shown schematically in FIG. 2) can be caused by the weight of the rail vehicle consist 20 exceeding the instantaneous torque provided by electric traction motors. Once rollback starts to happen, increasing backward movement 611 of the rail vehicle consist 20 requires increasingly larger forward torque (ordered movement 515) in order to stop the rail vehicle consist. Frequently, brakes must be reapplied and another attempt must be made at forward motion.

Rollback of the rail vehicle consist 20, as illustrated schematically in FIG. 2, can lead to impacts between the rail vehicle consist 20 and the loading/unloading equipment 16. Rollback also can lead to a condition where the rail vehicle consist 20 rests against the loading/unloading equipment 16 with sufficient force to interfere with operation of the equipment. Such impacts or interferences can damage the rail vehicle consist and/or the loading/unloading equipment, causing repair expense and downtime.

With reference to FIG. 3, aspects of the invention relate to a system for controlling a rail vehicle 24 a, by which rollback of the rail vehicle is prevented. In particular aspects, the system includes an on-board transceiver 202 of the rail vehicle 24 a. The on-board transceiver 202 sends and receives signals in communication with an off-board control unit 204. The on-board transceiver 202 also includes hardware and software for controlling operation of the rail vehicle 24 a. In particular, the on-board transceiver 202 is operatively connected for controlling traction and braking of the rail vehicle 24 a. The on-board transceiver 202 can be configured in various modes of operation. For example, in a rollback prevention mode, the on-board transceiver 202 adjusts traction motors 206 of the rail vehicle 24 a to achieve a pre-determined minimum tractive effort prior to releasing a braking system 208 of the rail vehicle.

FIG. 4 illustrates details of a tower control system 200 according to embodiments of the invention. The tower control system may include a tower equipment module 210 that houses a tower transceiver 212 for intermediating communication between the off-board control unit 204 and the on-board transceiver 202. The tower equipment module also may house an integrated processor module (IPM) 214 and a power converter 216. In some embodiments, the power converter receives 120 Vac and supplies 13.6 and 72 Vdc.

As shown in FIG. 4, according to one embodiment of the invention, the off-board control unit 204 includes multiple displays 218 on which a desired speed setting and measured vehicle speed are shown, as well as an operator control unit (OCU) 220. Each display is a remote session based device connected to the IPM 214, which handles all control signals and consist data for the operator displays 218. The OCU 220 includes at least the following controls: a multi-position selector 222 as well as a PARK button 224 and a STOP button 226. In some embodiments, the OCU also may include an auxiliary display 228 as shown. In some embodiments, the selector 222 may include a dial, a switch, a position encoder, or any equivalent device suitable for selecting among more than two options. In some embodiments, the buttons 224, 226 may be spring-return push buttons. Toggle switches, sliders, or the like are equally suitable. In certain embodiments, the functions of the two buttons 224, 226 may be combined into a single component, for example, a three-way selector switch. In select embodiments the functions of the two buttons 224, 226 may be combined into the selector 222, or the buttons may be mounted on the selector. The selector 222 as well as the buttons 224, 226 and the optional display 228 are shown and described herein as being physically separate components within an assembled unit, however, one of ordinary skill will appreciate that the displays 218 and the OCU 220 equally can be implemented partly or entirely via a single advanced interface such as a touch-screen.

The displays 218, 228 and the OCU 220 are coordinated by a computing device 230. “Computing device” as used herein refers to either a general purpose integrated circuit, a custom ASIC, an FPGA, a custom analog circuit, or other like device. As shown in FIG. 3, the computing device 230 is connected with the integrated processor module 214 via a point-to-point high-level data link control (“HDLC”) layer. In certain embodiments, the functionality of the computing device 230 may be implemented in the IPM 214 itself.

As illustrated in FIG. 5, the computing device 230 is configured to implement a continuous-loop control process 400 for generating and sending commands 407 to the on-board transceiver 202 via the IPM 214 and the tower transceiver 212. In implementation of the process 400, the computing device 230 makes use of a working memory 401. The working memory 401 may be composed of any electronically or optically read-writeable media, such as EEPROM, NAND flash, SDRAM, a hard drive, an optical disc, vacuum tubes, a capacitor bank, or other equivalent structures apparent to those of ordinary skill.

Each iteration of the process 400 includes a step 402 of checking and setting a mode of operation 403 of the off-board control unit 204. For example, pressing one of the STOP button 224 or the PARK button 226 establishes a corresponding mode of operation 403 of the off-board control unit 204 that causes the computing device 230 to generate and send to the on-board transceiver 202, via the tower transceiver 212, commands that idle the traction power system and that order braking of a locomotive 24 (or other powered rail vehicle) or of the entire rail vehicle consist 20, respectively.

After checking the mode of operation, the process 400 proceeds to a step 404 of receiving signals from the on-board transceiver 202 and/or from other sources within the rail yard 10 including the unloading equipment 16 or the indexing equipment 22. (Here “rail yard” is meant to include any arrangement of tracks off of a main line, including humpyards, sorting yards, or loading/unloading operations as discussed above.)

The computing device 230 stores received signals in the working memory 401 as on-board data 405. The on-board data 405 may include a measured speed “M” as well as indications that braking has been applied or that a braking order has been received in the rail vehicle where the on-board transceiver is installed. The measured speed “M” may be obtained by the on-board transceiver 202 from a control system on some rail vehicles (e.g., a locomotive control system on some locomotives) or from a trainline interface module (TIM) on some other locomotives or other rail vehicles.

Next, at a step 406 the computing device 230 generates commands 407 to be sent to the on-board transceiver. The commands 407 are generated according to an algorithm, which corresponds to the mode of operation 403. The algorithm generates the commands 407 with reference to the on-board data 405 and further with reference to control data and internal signals 408 that are stored in the working memory 401. Exemplary modes of operation 403, and on-board data 405, have been discussed above. The control data and internal signals 408 may include the braking parameter “P”, a preset speed limit “L”, a selector position “H”, and an ordered speed “O”. At a step 410 the tower control system 200 then sends the commands 407 to the on-board transceiver 202 before looping back to again check for control data input from the off-board control unit 204.

According to aspects of the present invention, the computing device 230 is configured to establish a rollback prevention mode of operation and to execute a first algorithm 500, as shown in FIG. 6A, in response to the lead locomotive 24 a (or other lead powered rail vehicle) being halted at any location within one or more pre-determined areas of the rail yard 10. As part of the first algorithm 500, the computing device 230 directs the on-board transceiver 202 to execute a second algorithm 600, as shown in FIG. 6B. Thus, the two FIGS. 5 and 6 should be considered together.

FIG. 6A shows that at step 502 of the algorithm 500, the computing device 230, within the off-board control unit 204, checks whether the lead locomotive 24 a (or other lead powered rail vehicle) is stopped. If not, the computing device 230 will exit the algorithm. At step 504, the computing device 230 receives a signal 505 indicative of the location of the lead locomotive 24 a (or other lead powered rail vehicle), and compares the indicated location to a rollback prevention map or table 506. In case the indicated location is not within the mapped area or is not listed in the table, then the computing device 230 exits the algorithm 500. However, in case the indicated location is mapped on the rollback prevention map 504, or listed in an rollback prevention locations lookup table, then at step 508 the computing device 230 inserts a rollback prevention mode signal into the commands 407. This signal initiates in the on-board transceiver 202 a rollback prevention mode 600, as shown in FIG. 6. Under the rollback prevention mode 600, the on-board transceiver 202 is configured to receive certain additional signals from the off-board control unit 204, as follows.

Still referring to FIG. 6A, at step 510, the computing device 230 accesses the rollback prevention map 504, or an equivalent lookup table, to find a minimum tractive effort parameter 511 corresponding to the location 501. For example, the minimum tractive effort parameter 511 may be determined during commissioning of the tower control system 200. The computing device 230 then inserts into the commands 407 a signal that encodes the minimum tractive effort parameter 511.

At step 512, the computing device 230 accesses the rollback prevention map 504, or an equivalent lookup table, to find a braking parameter 513 corresponding to the location 501. For example, the braking parameter 513 may be determined during commissioning of the tower control system 200. The computing device 230 then inserts into the commands 407 a signal that encodes the braking parameter 515.

At step 514 the computing device 230 receives from the multi-position selector 222 a signal ordering movement of the lead locomotive 24 a (or other lead powered rail vehicle). The computing device 230 generates an ordered movement 515 and forwards a corresponding signal to the on-board transceiver 202. The computing device 230 then proceeds to step 516 of waiting to receive on-board transceiver status signals 601.

Referring to FIG. 6B, at step 602, the on-board transceiver 202 receives the rollback prevention mode signal. At step 604, the on-board transceiver 202 receives the minimum tractive effort parameter 511 and the braking parameter 513. At step 605, the on-board transceiver 202 applies at least the brakes of the lead locomotive 24 a (or other lead powered rail vehicle), and possibly additional brakes of the rail vehicle consist 20, according to the braking parameter 513. At step 606, the on-board transceiver 202 receives the ordered movement 515 and increments a throttle notch setting (“throttle up”) until a monitored tractive effort 607 matches the minimum tractive effort parameter 511. Then at step 608, the on-board transceiver 202 releases at least the brakes 208 of the lead locomotive 24 a (or other lead powered rail vehicle). At step 608 the on-board transceiver 202 also releases any other brakes that are applied, for example, the automatic brakes of the rail vehicle consist 20 in case the rail vehicle consist is in a parked condition Immediately the on-board transceiver 202 proceeds to step 610 of checking whether the ordered movement 515 corresponds to a monitored movement 611, which includes a direction of motion as well as the measured speed “M” that was discussed with reference to FIG. 4.

In case the monitored movement 611 is matched with the ordered movement 515, then the on-board transceiver 202 declares a “movement” status signal at step 612. In case the monitored movement 611 does not match the ordered movement 515, then at step 614 the on-board transceiver 202 declares a “rollback” status signal and proceeds to apply automatic and independent brakes (“emergency braking”) at step 616.

In some embodiments, step 610 of checking for a match is accomplished by instantaneous or “snapshot” comparison of the directions of measured movement 611 and ordered movement 515. Thus, for example, in case the speed of ordered movement 515 is +0.5 mph (+0.2 m/s), while the monitored movement 611 is −0.2 mph (−0.09 m/s) (directions do not match), then a rollback is declared.

In other embodiments, step 610 is accomplished in a first noise-managed mode by comparing ordered movement 515 to monitored speed and direction 611 on a time integral basis, using one or more threshold value criteria. That is, referring to FIG. 6C, monitored movement 611 is continually compared to a first threshold value 630. In case the first threshold value is exceeded, at step 632 the monitored movement 611 is integrated over a pre-determined period 634 to produce a cumulative traveled distance 636, while at step 638 the ordered movement is integrated over the same period to produce a cumulative ordered distance 640. Then at step 642 a second threshold value 644 is compared to the cumulative traveled distance 636, or to a difference 646 between the cumulative traveled distance and the cumulative ordered distance 640. For example, the first threshold value 630 may be as small as −0.02 mph (0.009 m/s), the pre-determined period 634 may be 10 seconds, while the second threshold value 644 may be as large as 33 ft (10 m). The threshold values 630, 644, and the time period 634, are configurable at least at commissioning of the tower control system 200.

Referring back to FIG. 6A, in case the signal received at step 516 indicates proper movement, the computing device 230 exits the algorithm 500. On the other hand, in case the signal received at step 516 indicates rollback, the computing device 230 performs step 518 of displaying an alert.

FIG. 7 shows more generally the algorithms 500 and 600, including additional steps 702, 704 of monitoring speed and direction of the rail vehicle consist 20 as well as optional steps 706, 708 of displaying a braking alert and awaiting an operator response or confirmation, prior to step 614 of declaring rollback.

FIGS. 8A-8B show another implementation of the algorithms 500, 600, wherein certain steps are performed in the computing device 230, rather than at the on-board transceiver 202. In particular, FIG. 8A shows that step 606 (throttling up to match the monitored tractive effort 607 to the minimum tractive effort parameter 511) and step 608 (releasing brakes) can be accomplished by remote commands from the off-board control unit 204, rather than autonomously by the on-board transceiver 202. Meanwhile FIG. 8B shows that the function of step 610 (comparing ordered movement to monitored movement) still can be accomplished by the on-board transceiver 202 using sensors aboard the rail vehicle 24 a.

Thus, in embodiments, a system for controlling a rail vehicle includes an off-board control unit that is configured for communication with an on-board transceiver, which is mounted in the rail vehicle. The off-board control unit is further configured to receive a first signal indicative of a location of the rail vehicle and to, in response to the indicated location of the rail vehicle matching a pre-defined list of rollback locations, send to the on-board transceiver a second signal indicative of a tractive effort parameter corresponding to at least the indicated location of the rail vehicle. In select embodiments, the system may also include the on-board transceiver, which may be configured to adjust and monitor a tractive effort of the rail vehicle and to control applying brakes of the rail vehicle until the monitored tractive effort at least matches the tractive effort parameter. In such embodiments, the off-board control unit also may be configured to set a braking parameter based on the indicated location of the rail vehicle and to transmit the braking parameter to the on-board transceiver, while the on-board transceiver may be configured to control applying the brakes according to the braking parameter. Further, the on-board transceiver may be configured to monitor rail vehicle movement, to compare the monitored movement to an ordered movement, and to control application of emergency brakes in response to a mismatch of the monitored movement and the ordered movement. For example, the on-board transceiver may be configured to control application of the emergency brakes according to the braking parameter. In select embodiments, the on-board transceiver may be configured to compare the monitored movement to the ordered movement on a time integral basis. In some embodiments, the on-board transceiver also may be configured to send to the off-board control unit, in response to a mismatch of the monitored movement and the ordered movement, a request for a third signal to apply the brakes of the rail vehicle. In such embodiments, the off-board control unit may be configured to, in response to the request received from the on-board transceiver, display an operator prompt and receive an operator input whether to apply the brakes. The third signal for applying the brakes may include a braking parameter based on the indicated location of the rail vehicle. Further, the off-board control unit may be configured to monitor tractive effort of the rail vehicle, and to send the on-board transceiver a fourth signal for releasing the brakes, once the tractive effort of the rail vehicle matches or exceeds the tractive effort parameter. However, in some embodiments, the off-board control unit may be configured to send the fourth signal for releasing the brakes, pursuant to a request received from the on-board transceiver. In some embodiments, the off-board control unit may be configured to send a fifth signal for establishing a rollback prevention mode, based on the indicated location of the rail vehicle matching the pre-defined list of rollback locations; the on-board transceiver may be configured to establish a rollback prevention mode on receipt of the fifth signal from the off-board control unit.

In aspects, a method, e.g., a method for preventing rollback of a rail vehicle from a stopped condition, includes receiving a first signal indicative of the rail vehicle's location and, in response to the first signal, selecting from a lookup table one of a first plurality of pre-determined values of a braking parameter and selecting from the lookup table one of a second plurality of pre-determined values of a tractive effort parameter. The method then includes transmitting to the rail vehicle a second signal ordering movement of the rail vehicle from the stopped condition. The second signal includes the selected value of the braking parameter for controlling application of brakes of the rail vehicle and the selected value of the tractive effort parameter for establishing tractive effort of the rail vehicle. In some aspects, the method also includes receiving the second signal at the rail vehicle, and, in response to the second signal, applying the brakes of the rail vehicle, according to the selected value of the braking parameter; establishing the tractive effort of the rail vehicle, according to the selected value of the tractive effort parameter; and, releasing the brakes of the rail vehicle to establish movement of the rail vehicle from the stopped condition. In certain aspects, the first signal is received at an off-board control unit that is not installed on the rail vehicle. In select aspects, the second signal is transmitted from the off-board control unit to an on-board transceiver that is installed on the rail vehicle.

Embodiments include a system for controlling a rail vehicle, which includes an on-board transceiver mounted in the rail vehicle and operatively connected with at least one traction motor and at least one brake of the rail vehicle. The on-board transceiver is configured to receive from an off-board control unit a first signal for establishing a rollback prevention mode. In its rollback prevention mode, the on-board transceiver is configured to receive from the off-board control unit a second signal indicative of a required tractive effort and a third signal indicative of a required braking force, and to control maintaining the required braking force until attaining the required tractive effort. The on-board transceiver may be further configured to control release of the braking force on attaining the required tractive effort, to monitor movement of the rail vehicle, to compare the monitored movement to an ordered movement, and to control application of the required braking force according to the third signal, in case the monitored movement does not match the ordered movement. In certain embodiments, the on-board transceiver may be configured to compare the monitored movement to the ordered movement on a time integral basis.

In other embodiments, a system for controlling a rail vehicle includes an off-board control unit that is not mounted in the rail vehicle and an on-board transceiver that is mounted in the rail vehicle. The off-board control unit is configured to receive a first signal indicative of a location of the rail vehicle and to send, in response to the first signal, a second signal indicative of a minimum tractive effort parameter and a third signal indicative of a braking parameter. The on-board transceiver is operatively connected with at least one traction motor and at least one brake of the rail vehicle, and is configured to receive the second and third signals from the off-board control unit. The on-board transceiver is further configured to control maintaining the brake output at or above a level of the braking parameter until the traction motor output at least matches a level of the minimum tractive effort parameter.

It will be appreciated that the invention is not limited by the preceding description, which is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the invention, they are by no means limiting and are exemplary embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, terms such as “first,” “second,” “third,” “fourth,” “fifth,” “upper,” “lower,” “bottom,” “top,” etc. are used merely as labels, and are not intended to impose numerical or positional requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. §122, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.

This written description uses examples to disclose several embodiments of the invention, including the best mode, and also to enable one of ordinary skill in the art to practice the embodiments of invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising,” “including,” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.

Since certain changes may be made in the above-described system and method for rollback prevention, without departing from the spirit and scope of the invention herein involved, it is intended that all of the subject matter of the above description or shown in the accompanying drawings shall be interpreted merely as examples illustrating the inventive concept herein and shall not be construed as limiting the invention. 

1. (canceled)
 2. A system for controlling a rail vehicle, comprising: an off-board control unit that is configured for communication with an on-board transceiver, the on-board transceiver being mounted in the rail vehicle, the off-board control unit further configured to, in case the rail vehicle is stopped, receive a first signal indicative of a location of the rail vehicle and further configured to, in response to the indicated location of the rail vehicle matching a pre-defined list of rollback locations, send to the on-board transceiver a second signal indicative of a tractive effort parameter and a braking parameter, said parameters corresponding to at least the indicated location of the rail vehicle; and the on-board transceiver, wherein the on-board transceiver is configured to adjust and monitor a tractive effort of the rail vehicle and to control applying brakes of the rail vehicle,, according to the braking parameter, until the monitored tractive effort at least matches the tractive effort parameter, is further configured to release the brakes after the monitored tractive effort matches the tractive effort parameter, and is further configured to, after releasing the brakes, monitor rail vehicle movement, compare the monitored movement to an ordered movement, and in response to a mismatch of the monitored movement and the ordered movement, transmit to the off-board control unit a third signal related to applying the brakes of the rail vehicle.
 3. (canceled)
 4. A system as claimed in claim 2, wherein the on-board transceiver is configured to monitor rail vehicle movement, to compare the monitored movement to an ordered movement, and to control application of emergency brakes in response to a mismatch of the monitored movement and the ordered movement.
 5. A system as claimed in claim 4, wherein the off-board control unit is configured to set a braking parameter based on the indicated location of the rail vehicle, and the on-board transceiver is configured to control application of the emergency brakes according to the braking parameter.
 6. A system as claimed in claim 4, wherein the on-board transceiver is configured to compare the monitored movement to the ordered movement on a time integral basis.
 7. (canceled)
 8. A system as claimed in claim 2, wherein the off-board control unit is configured to, in response to the third signal generated by the on-board transceiver, display an operator prompt and receive an operator input whether to apply the brakes.
 9. A system as claimed in claim 2, wherein the off-board control unit is configured to set a braking parameter based on the indicated location of the rail vehicle, and to send a fourth signal for applying the brakes, wherein the fourth signal for applying the brakes includes the braking parameter.
 10. A system as claimed in claim 2, wherein the off-board control unit is configured to monitor tractive effort of the rail vehicle, and to send the on-board transceiver a fourth signal for releasing the brakes, once the tractive effort of the rail vehicle matches or exceeds the tractive effort parameter.
 11. A system as claimed in claim 10, wherein the off-board control unit is configured to send the fourth signal for releasing the brakes, pursuant to a request received from the on-board transceiver.
 12. A system as claimed in claim 2, wherein the off-board control unit is configured to send a fifth signal for establishing a rollback prevention mode, based on the indicated location of the rail vehicle matching the pre-defined list of rollback locations, and the on-board transceiver is configured to establish a rollback prevention mode on receipt of the fifth signal from the off-board control unit.
 13. A method for preventing rollback of a rail vehicle starting from a stopped condition, said method comprising: receiving in an off-board control unit a first signal indicative of the rail vehicle's location; in response to the first signal, in the off-board control unit selecting by a computer algorithm one of a first plurality of pre-determined values of a braking parameter and selecting by a computer algorithm one of a second plurality of pre-determined values of a tractive effort parameter; transmitting from the off-board control unit to an onboard transceiver of the rail vehicle a second signal ordering movement of the rail vehicle from the stopped condition, wherein the second signal comprises the selected value of the braking parameter for controlling application of brakes of the rail vehicle and the selected value of the tractive effort parameter for establishing tractive effort of the rail vehicle; receiving the second signal at the onboard transceiver; and, by the onboard transceiver, in response to the second signal: applying the brakes of the rail vehicle, according to the selected value of the braking parameter; establishing the tractive effort of the rail vehicle, according to the selected value of the tractive effort parameter; releasing the brakes of the rail vehicle to establish movement of the rail vehicle from the stopped condition; by the onboard transceiver, after releasing the brakes, monitoring rail vehicle movement, comparing the monitored movement to an ordered movement, and in response to a mismatch of the monitored movement and the ordered movement, transmitting to the off-board control unit a third signal related to applying the brakes of the rail vehicle.
 14. A method according to claim 13, wherein the third signal is a request to the off-board control unit for permission to apply the brakes. 15.-16. (canceled)
 17. A system for controlling a rail vehicle, said system comprising: an on-board transceiver mounted in the rail vehicle and operatively connected with at least one traction motor and at least one brake of the rail vehicle, said on-board transceiver configured to receive from an off-board control unit a first signal for establishing a rollback prevention mode, and further configured in said rollback prevention mode to receive from the off-board control unit a second signal indicative of a required tractive effort and a third signal indicative of a required braking force, to control maintaining the required braking force until attaining the required tractive effort, to control release of the braking force on attaining the required tractive effort, to monitor movement of the rail vehicle, to compare the monitored movement to an ordered movement, and to, in response to a mismatch of the monitored movement and the ordered movement, transmit to the off-board control unit a third signal related to applying the brakes of the rail vehicle.
 18. (canceled)
 19. A system as claimed in claim 17, wherein the on-board transceiver is configured to compare the monitored movement to the ordered movement on a time integral basis.
 20. A system for controlling a rail vehicle, comprising: an off-board control unit that is configured to receive a first signal indicative of a location of the rail vehicle and to send, in response to the first signal, a second signal indicative of a minimum tractive effort parameter and a third signal indicative of a braking parameter; and an on-board transceiver mounted in the rail vehicle, operatively connected with at least one traction motor and at least one brake of the rail vehicle, and configured to receive the second and third signals from the off-board control unit, wherein the on-board transceiver is configured to control maintaining the brake output at or above a level of the braking parameter until the traction motor output at least matches a level of the minimum tractive effort parameter, is configured to release the brake output after the traction motor output matches the minimum tractive effort parameter, is configured to monitor rail vehicle movement, and is configured to, in response to a mismatch between the monitored movement and an ordered movement, transmit to the off-board control unit a third signal related to applying the brakes of the rail vehicle. 